1. Field of the Invention
This invention relates to improvements in a side door hinge mechanism in a motor vehicle through the utilization of a quadric rotary link mechanism.
2. Description of the Related Art
In most cases, the side door in a motor vehicle, e.g. passenger car has heretofore been installed in a manner to be rotatable about a hinge affixed to a vehicle body for opening or closing. In order to allow an occupant of the motor vehicle to open or close the side door for getting in and out of the motor vehicle, a door opening angle commensurate to the total length of the side door is required. At this time, when a space outwardly of the motor vehicle is small, there are many cases where it is difficult for the occupant to get in and out of the vehicle because the side door cannot be opened sufficiently.
In contrast thereto, as disclosed in Japanese Utility Model Laid-Open (Kokai) No. 46014/1982 or 101263/1980 for example, here has been proposed a side door hinge mechanism through the utilization of a quadric rotary link mechanism, wherein the quadric rotary link mechanism comprises: a rotary link interconnecting a point on a body of the vehicle and another point on a side door as rotary centers out of two points spaced apart from each other on the body and two points spaced apart from each other on the side door; another rotary link interconnecting the other point on the body and the other point on the side door as being centers; a portion between the two rotary centers on the body; and another portion between the two rotary centers on the side door.
The side door hinge mechanism utilizing the above-described quadric rotary link mechanism makes it possible for the occupant to reduce the necessary space outwardly of the motor vehicle while securing a space at his feet. In consequence, even when the space outwardly of the motor vehicle is small, the occupant can get in and out of the motor vehicle by opening or closing the side door.
In the side door hinge mechanism utilizing the above-described quadric rotary link mechanism, the rotary center shaft of the side door is spaced apart a rotary link's length from the rotary center shaft of the body, whereby a moment acting on the side door hinge due to a load of the side door becomes high and also a high load due to this moment is applied to a portion for mounting the rotary center shaft of the side door.
In consequence, in order to increase the rigidity for supporting the side door, it is necessary to mount a plurality of door hinges arranged in the vertical direction.
However, when the plurality of side door hinges are mounted in the vertical direction as described above, such disadvantages are presented that these rotary center shafts should be aligned with each in the vertical direction and the works of mounting and adjusting are troublesome.
Further, the rigidity of the surfaces of the body and the side door, to which the above-described rotary center shafts, particularly, the rigidity of the surface of the side door should be made considerably high. To satisfy this requirement, such a disadvantage is presented that the weights of the side door and of the door hinge should be increased.
More specifically, if the rigidity of the side door is low, then, in conjunction with the long length of the door hinge, i.e. the rotary link, for example the rigidity in the vertical direction, torsional rigidity and rigidity for bearing an excessive opening of the side door when the side door is opened become low, such disadvantages are presented that the side door is displaced downwardly, distorted or deformed when fully opened.
Further, if the rigidity is low when the door is closed, such a disadvantage is presented that the ill-fitting to the body occurs.
Here, in the side door hinge mechanism of the type described, in order to improve accuracies of the rotary center shafts of the arms constituting the quadric rotary link devices, such an arrangement may be adopted that these rotary center shafts are supported on a body side base and a door side base, each of which is formed into a vertically long plate shape, and these body side base and door side base are tightened and fixed to the vehicle body and the side door through bolts.
Such disadvantages are presented that, when the body side base and the door side base, which are long members, are closely tightened and fixed at the whole surfaces thereof opposed to the vehicle body and the side door to the vehicle body and the side door, if the motor vehicle being previously assembled thereto with the side door hinge mechanism is passed through a coating process, then the spaces, to which the coating cannot be applied between the body side base and the vehicle body and between the door side base and the side door, occur in fairly large areas, and moreover, in a coating drying furnace, the body side base is closely attached to the door side base, whereby heat increase in the closely attached surfaces is hindered, so that insufficiently dried portions may occur.
Provided, normally, between the vehicle body and the side door is a power source for the power window regulator or a wire harness for a control system, for example, of the side door.
For the side door mounted through the above-described side door hinge mechanism, the wire harness is provided, passing through a space formed in the vertical direction between the top and bottom quadric rotary link devices.
In this case, differing from the case of using an ordinary hinge, the side door is greatly moved in the longitudinal direction and in the widthwise direction of the vehicle body during its opening or closing, whereby the wire harness must be elongated as commensurate to this between the side door and the vehicle body.
When the wire harness is made elongate as described above, there is a possibility that the wire harness is bitten in between the arms and the door side base or the body side base, or between the arms during opening or closing of the side door.
When the main arm is formed integrally in the vertical direction in order to increase the rigidity of the side door hinge mechanism, it is necessary to provide a space in the intermediate portion in the vertical direction of the main arm and the wire harness is passed through this space, so that the main arm may not interfere with the wire harness.
Even when the main arm is formed therein with the space for allowing the wire harness to pass therethrough as described above, the wire harness is formed elongated between the side door and the vehicle body as aforesaid, whereby there is presented such disadvantages that the main arm comes into contact with the wire harness to make the coating of the main arm peeled off, and the wire harness itself is worn.